With the advent of suspended ceiling structures, in which a rectangular grid structure was suitably supported and adapted to carry rectangular ceiling panel tiles or the like, the supporting grid structure initially consisted of a plurality of spaced parallel main runners which were connected at spaced intervals by transversely extending cross-runners to form a rectangular grid structure in which the ceiling panel tiles were supported, either with the grid structure being completely concealed or portions thereof being exposed to view.
In such suspended ceiling structures, the main runners were required to be set at comparatively exact spacing distances and the cross runners secured thereto in comparatively accurately spaced intervals. In such constructions, the ends of the cross runners usually intersected and were interlocked with the main runners to provide a grid structure having specific set or fixed spacing between the respective main and cross runners.
In recent years do-it-yourself installations have become more and more popular, wherein the unskilled homeowner or the like purchases the ceiling structure in kit form and performs the installation himself. Difficulties often arose as a result of the requirement of accurate spacing between parallel runners, necessitating accurate layout and mounting of the respective runners, a relatively difficult operation for persons unskilled in the art. To avoid these difficulties, efforts have been made to provide structures that did not require the accurate layout and mounting of previous designs.